The overall aims were to learn more about factors affecting fertility in Swedish beef sires in general and in yearling beef bulls in particular, focusing mainly on sexual maturity and hind limb health finding useful tools in order to be able to routinely perform a complete bull breeding soundness evaluations in Swedish beef bulls. Semen was collected from yearling beef bulls, postmortem, and the sperm morphology was evaluated. Using a strict definition, based on sperm morphology, we could demonstrate that less than half the number of the bulls was considered sexually mature at 12 months of age. Samples collected by transrectal massage were compared with the two most commonly used collection methods; artificial vagina and electroejaculation, and with samples collected by cauda epididymal dissection postmortem. Sperm morphology in semen collected by transrectal massage was as representative as in samples collected by artificial vagina and electroejaculation and to some extent also in those collected postmortem. However, reduction in volume, concentration and motility would need to be considered, especially if semen is collected outdoors under suboptimal conditions. In conclusion, the transrectal massage technique is a very useful semen collection method in the field when no other collection method is possible, thus enabling a complete bull breeding soundness evaluation. Femorotibial, femoropatellar (stifle), tarsocrural, talocalcaneus, and proximal intertarsal joints from young beef sires with impaired fertility, but no signs of lameness, were examined postmortem regarding the presence of joint lesions. A majority of the bulls had severe, bilateral lesions referred to as osteoarthritis secondary to osteochondrosis dissecans. We think that the osteoarthritis present in the hind limbs must have contributed to the infertility, rendering the bulls difficulties in mounting. The fact that most of the lesions were bilateral, could explain the absence of clinical lameness. The results of this study indicate that the poor fertility reported in these beef bulls can be a result of joint problems, secondary to osteochondrosis. Thus, joint lesions should always be taken into consideration as a contributory cause of reproductive failure in beef sires with or without symptoms of lameness
